Absolutely. It demonstrated that the way I was running, I was in anaerobic territory 90% of the time. When I got that fuckin' thing (before Bluetooth), it made me walk for like 3 weeks. I initially bought it because it was the best integrated with my ergometer. I later used it running, biking, walking, you name it. I quit because it started getting stinky quickly and got bossy... but I keep toying with the idea of getting another that just talks to the phone.
I got the Polar H7 heart rate sensor today, and just finished my first workout with Endomondo. Starting with Couch to 5k because I'm horribly out of shape: SO MUCH STATS, I love it. I can even get the GPS data and put it in ArcGIS if I'm really bored. But best of all is that it just tells me what to do. And there's a beautiful park right next door for me to run through. Thanks for the indirect tip, bro. eightbitsamurai what about you?
It was like $90? In part I bought it so that I kinda have to run - to reduce the price per run. Terrible strategy, I know. I like the sensor. It's very accurate and even though I had some setup / Bluetooth issues, once it works it just works. Goes around your chest, but it's not one of those bands that you feel the entire run. Since I always carry my phone around for music, I didn't go for one of those watches because my phone already has GPS, gyro and accelerometers.